The basic objective of the proposed research is to perfect and evaluate implant designs using porous titanium as a vehicle for obtaining tissue attachment in an animal model in which near human usage conditions can be obtained. Designs which have been proven clinically successful in dogs under unloaded or lightly loaded conditions will be modified and placed in rhesus monkeys and fitted with anatomical crowns in full occlusion. The basic variable of root size will be explored, with implants which will be placed in occlusion for periods of 1 to 2 years. A corollary objective is to develop better techniques for histopathological analysis. Decalcified and undecalcified sections, reflected light microscopy, and scanning electron microscopy techniques will be perfected and the evaluation of implant performance by each technique will be compared. The successful conduct of this research program will lead to a concrete judgment on the possibility for using an inert porous medium as a tissue attachment vehicle in human implants.